Radiotherapy is a therapeutic approach that irradiates a lesion in a body of a patient (object under test) with a radioactive ray to destroy the lesion. At this time, normal tissues are also destroyed unless an accurate position of the lesion is irradiated with a radioactive ray.
Therefore, at the time of therapeutic planning, the position of the patient is determined first, then a perspective image in the body of the patient is photographed in advance by CT (Computed Tomography) apparatus, the position of the lesion in the body of the patient is figured out three dimensionally from the perspective image, and then a direction of irradiation and a strength of the irradiation of the radioactive ray, which reduce the probability of irradiation of the normal tissue on the basis of the position of the lesion, are determined. At the time of therapy, a new perspective image of the patient is photographed, and a medical doctor (user) inputs corresponding points on the new perspective image and the perspective image taken at the time of therapeutic planning, performs positional alignment of the patient according to the therapeutic planning, and irradiates the lesion with a radioactive ray.
However, since the therapy is repeated by a plurality of times, the positional alignment of the patient needs to be performed at every therapy. In addition, since the patient needs to maintain the same posture from the positional alignment until the termination of the irradiation of the radioactive ray, the patient suffers from a significant burden. Therefore, this positional alignment is desired to be performed accurately in a short time.
Accordingly, it is an object of the invention to provide a medical image processing apparatus, medical image processing method, and a radiotherapy system which assist a user to facilitate input of corresponding points for the positional alignment on a plurality of photographed perspective images of the object under test.